This invention relates generally to twist canisters and in particular to a twist canister which provides a means for conducting electrical and fluid conduits across a pivoting joint using a minimum of space minimum length of conduit and requiring a minimum amount of energy to accomplish the required pivotal movement.
Many devices for conducting electrical signals and fluid conduits across pivotal joints are known in the art. One such method utilizes sliding contacts such as slip rings for electrical signals and similar rotatable joints for fluid conduits. These mechanisms must be used when unlimited rotation is required. However, they create many problems such as leakage in fluid lines, electrical noise on signal lines and high electrical current transmission. Where only limited rotation is required, a twist capsule is the preferred solution.
Twist capsules of the prior art often require relatively large amounts of power to accomplish the required rotation since they usually require bending, folding and sliding of the conduits. When bending and/or folding is required to accommodate the rotation, relatively long conduits are required. In addition, bending, folding and sliding conductors results in substantial wear which increases the chance of failure of the conduit. In certain critical applications, such as in sophisticated aircraft structures, such a failure can be catastrophic.
The present invention overcomes these problems by first, minimizing the bending or flexing of the conduits, secondly, the conduits are pre-flexed in order to minimize conduit motion and the conduits are pre-flexed half of the total rotation required such that the conduits are in an unflexed condition at a point half way in the rotation. In addition, the flexure required takes place as translation in a vertical plane rather than horizontal which minimizes the space required for the total assembly. Where the conduit does not accept sufficient torsional motion, swivel fittings may be used . This combination of features insures long life for the conduits and minimum power for actuation.